From here on out, Kiganjou (Demon Rock Castle) will be called Sovereign Rock Castle as it was originally in Crunchyroll’s subs. Why? Because in the new perfect edition manga, the data section for Kiganjou is written as Sovereign Rock Castle. In the old Tankobon, it was written as just Kiganjou. Sovereign Rock Castle may not be the actual translation, but the author wanted it as such, that’s why it was written as Sovereign instead of Demon in the perfect edition manga.